Rotary reciprocating compressor



May 2l, 1940. s. A. LIMPE'RT E1- AL.

ROTARY RECIPROCATING" COMPRESSOR FiledJuly 24, 1935 s sheets-s118951 May21, 1940- s. A. I uvn---uRT Er Al.

ROTARY RECIPROCAT'ING COMPRESSOR Filed July 2 4, 1935 6 Sheets-Sheet 2gsi jw) ATTORNEY.

May 2l, 1940.4 s. A. LIMPERT- ETAM. 2,201,188

ROTARY RECIPROCATING COPRESSOR /x' Filed Juiy 24, 1935 s sheets-sheet sT JET PRESSURE Raoucme VALVE I l V4 EvAPoRAToR May 2l, 1.940- s. A.LIMPERT Er Al.

` ROTARY RECIPROCATING COMPRESSOR Filed July 24, 1955 6 Sheets-Sheet 4 iMay-21, 1940.

x S. A. LIMPERT ET AL ROTARY nEcIPRooATING comREsson` 6 Sheets-Sheet 5Filed July 24, 1955 To :maf/VSE@ Hao/vy fmforo@ Patented May 21, l1940PATENT OFFICE ROTARY RECIPROCATING COMPRESSOR Sylvester A'. Limpert andAlexander S. Lmpert, Bay Shore, N. Y.

Applicationjuly 24, 1935, serial No. 32,863

2s claims. (o1. 23o-175) This invention relates to pneumatic compressionapparatus and has for its particular objects the provision of a simple,compact, cheap and unusually eiiicient mechanism which is quiet in op- 5eration andy ideally adapted for refrigeration and air conditioningpurposes. Further advantages of such mechanism are hereinafter setlforth.

In the accompanying drawings, wherein is illustrated certain embodimentsof our invention:

Figure l is a central, vertical section of a compressor unit embodyingour invention as especially designed for a refrigerating machine;

Figs. 2 and 3 are sections taken lon the line 2-2 and 3-3, respectively,of Fig. 1;

Fig. 4 is a vertical section, partly in elevation,

of the compressor unit shown in Fig. 1 but showing the cylinder in adiametrically opposite position;

Fig. 5 is a transverse section on the line 5--5 of Fig. 4;

Fig. 6 is a fragmentary elevation of the piston shown in Fig. 1,isolated;

Figs. 7 and 8 are ltransverse sections on the linel--l and 8-8respectively of Fig. l;

Fig. 9 is an elevation, partly diagrammatic of a complete refrigeratingunit embodying our invention which is intended for installation in aso-called domestic electrical refrigerator;

Fig. l0 is a vertical section, partly in elevation,

` of a compressor unit wherein a reciprocating piston is connected tothe rotatable housing;

Fig. l1 is a vertical section, partly in elevation,

of a further modification wherein the cylinder is vertically disposedand reciprocates without rotation thereof;

3 i Fig. 12 is a vertical section, partly in elevation,

, of another form of compressor unit, wherein aA vertical cylinderrotates and also reciprocates;

Fig. 13 is a fragmentary vertical section, partly Ain elevation, of afstill further-modificationshowing a compressor unit wherein portedvalves are employed;

Fig. 14 is a section on the line I4-I4 of Fig. 13 and Fig. 15 is adeveloped view of the internal surface of the cylinder, showing thegrooves or slots that are formed therein;

Fig. 16` is a diagrammatic view showing theV driving elements so locatedon the compressor shell and' driven cylinder as to eliminate relativereciprocation thereof; and

Fig. 17 is an elevation of a modified crank arm.

Referring to the drawings and the construction shown therein, thereference numerals I and 2 designate the bottom and top sections of therevolving hollow shell of our improved compressor the interior of saidshell constituting afluid receptacle, 2 a boss which functions as acounterweight, 3 the bolts for securing the two sections and aninterposed gasket 4 together, andi a pulley groove for the driving beltthat is formed 5 at the juncture of the two sections. The *lower sectionhas a reduced depending neck 6, the same having a central counterboredpassage, as indicated by the reference numerals 1 and 8, and opposingducts I0 which afford communication 10 between the portion 8 of suchpassage and a flared recess II which surrounds the upwardly projectinghollow boss or sleeve I2 formed on said neck 6 and which boss isprovided with a 1 lubrication aperture I3. A shank I5 of a stal5 tionarypiston member I6 is mounted in said sleeve I2, such shank extending atVan oblique angle, preferably at about 30 to the axis of the piston I6..The latter has a hollow chamber II formed therein which is incommunication with 2n a vertical duct I8- which extends through theshank I5 and is adapted to deliver compressed fluid externally of theshell, for example to a conduit that delivers compressed refrigerant tova condenser of a refrigerating unit (see Fig. 9). 25

An oblique duct I9 intersects the upper end of another vertical duct 20.which also extends through the shank I5, but is independent of the ductI8 and affords communication between the 4internal chamber of therevolving shell and an 30 external source of fluid supply, for examplethe evaporator on-the low side of a refrigerating unit (see Fig. 9). Theupper end of the chamber I1 is counterbored for the reception of a.gasket 22 and an insertible valve retainer unit 23, which 35 latter isthreaded into said piston, the same having a valve seat 24, a valve 25,preferably formed of three triangular metal sheets superimposed on eachother and each of which is of slightly less over-all length than theinternal diameter o of said unit 23, the same being retained. againstescape by a looped spring wire retainer 26 that is snapped into anannular groove formed in the inner wall of said unit 23.

` Said piston is preferably provided with piston s Vrings 23 and to thelower end' thereof is secured walls is accomplished. Said cylinder 35has a top terminal flange 36 and a lateral boss 31 to which is pinned acylindrical crank arm 38 which, in the construction shown in Fig. 1,projects at right angles to the longitudinal axes of both said cylinderand said piston I6. Another lateral boss 40 isformed on the outer wallof the cylinder and a hollow weighted member 4| is slidably mounted on abolt 42 that is threaded into said boss, said weight being normallydepressed when the machine is at rest by a compression spring 43 whichis mounted within the member 4| and reacts against the inner face of thehead of said bolt and the adjacent face of said hollow mem'- ber 4|. Acylinder head 45, together with a sealing gasket 46, are secured bymeans of cap screws 41 to the flanged end 36 ofthe cylinder. Said head45 has an annular recess 48 in which is an annularvvalve seat 48 againstwhich a disc valve 50 is adapted to periodically seat/said valve beinggenerally similar to the valve 25. QA looped spring wire retainer 5|,which is snappedi'into an annular groove formed on the inner wall ofsaid chamber 48, serves to loosely retain said valve in said chamber.

An angular arm 55, which is secured to a leaf spring 56 which is in turnsecured to the cylin-` der by means of a cap screw 51 and spacing washer58,carries a stop screw 59 upon which is mounted an adjusting nut 60which permits of the adjustment of said screw to such a position as tohold the Valve 50 oil.D of its seat 49 either when the machine is atrest and the parts are in the position shown in Fig. l or upon theinitial starting of the motor which operates the compressor, whereby thefree escape of refrigerant gas from the cylinder 35 will be permitteduntil such time as the weight 4| ies outwardly and under the urge ofcentrifugal force lifts arm 55 upwardly against a stop 6| that issecured to the cylinder head, whereupon said screw will be likewiseelevated out of contact with said valve 50 and the latter will bepermitted to function normally.

A lug 65 and also a pair of lugs 66, 66' are formed on the inner wall ofsection of the shell of the compressor and on the former is mounted abolt 61, the head 68 of which constitutes a saddle, and which isretained in said lug 65 by means of a nut 69. A cross bar 10 is securedto` the said lugs 66, 66', and a laminated leaf spring 1|, which issecured by means of a cap screw 12 `to said plate 10 and also to the lug66', serves as a bottom support for a substantially spherical centrallyapertured member 13, in which is slidably mounted the `cylindrical arm38. The position of the suport 61 is so adjusted as to cause saidspherical member 13 to slightly compress the spring 1| and thereby saidspherical member 13 is held against escape from said saddle 68 by saidspring 1|, irrespective of the rotary motion of said member 13 under theinfluence of the arm 38.

The neck 6 of section I of the shell is mounted on the outer raceway 15of a roller bearing, which raceway is snugly fitted in the enlarged boreof said neck 6, and the inner raceway 16 is shrunk on said slmnk I5. Therollers 11 are obliquely disposed to more eiectively take upy the thrustexerted by the rotation of said shell upon said bearing, all in the wellknown manner.

In order to prevent the escape of refrigerant and/or oil from the shellof the compressor, we provide sealing means, comprising a metal sleevewhich has a terminal flange on which is formed an eccentric annular rib8| that is adapted to permanently engage the outer end of the innerraceway 11. A flexible rubber or composition gasket 83y and a metalreinforcing washer 84 are interposed between the neck 6 and a centrallyapertured terminal cap 85 that is secured to said neck by cap screws 86.The central aperture b of washer 84 is of slightly larger` diameter thanthe maximum diameter of the `inner face of said bonnet 81 and a washer89 which surrounds the outer end of said sleeve 80. The shank I5 ismounted in the flanged block 95, being secured thereto by a set screw96, and said block is in turn mounted on a suitable base 91. Rubberblocks 99, which function as shock absorbers are loosely mounted in fourcorner recessesformed in the bottom of said base, and these blocks whicheach have a central cylindrical aperture |00 extending completelytherethrough are secured to the iioor on which the base 91 rests byscrews |0I. Apertures |00 are adapted to receive pins |02 that serve toloosely connect said blocks to said base 91, and these pins are ofsubstantially less diameter than said apertures |00, whereby as shown,but a very small portion of the perimeter of said pins will be inengagement with the inside surface of the aperture |00 and thusvibrations are effectively absorbed.

In Fig. 10 we have illustrated a construction of compressor wherein astationary, obliquely disposed cylinder |30 `is formed on the upper endof shank I5 which generally corresponds to shank |5 shown in Fig. l,except that the refrigerant intake conduit 20 intersects a right anglebore I9 which affords communication with the interior of the compressorshell or so-called crank case and the exhaust valve unit 53| is mountedin the recess formed on the inner surface of the bottom of saidcylinder. A rotary-reciprocating piston element |32 is mounted in saidcylinder, the same projecting through the open top thereof, and anintake valve unit |33, which controls the ow of refrigerant from thechamber of the compressor shaft into an` intake conduit |33 that extendscentrally through said piston, is mounted in the top of said piston; Anarm |34, which is secured to the` upper end of said piston, and projectsan exhaust valve |4| mounted in its upper end..

In order to prevent rotation of said piston relative to the cylinder apin |42 is mounted in the side of said piston, the same being adapted toproject into a key-way |43 that projects vertically along the iner wallof a cylinder |44, the same extending from the bottom thereof to a leveljust above the top of said pin or key |42. An inlet valve |45 ispositioned in the top of the cyilnder for controlling the admission ofrefrigerant gas from the chamber in the shell of the compressor. A ring|46 is rotatably mounted in an obliquely disposed peripheral groove |41that is formed on the outer wall of said cylinder and the crank arm 38is rigidly connected thereto.

. haust conduit I8'. The cylinder |65 has a closed In the modificationshown in Fig. 12, a vertically disposed piston |50 is employed, but thesame is mounted off-center with respect to the shank l5, and said pistonhas an vexhaust valve mounted in the upper end thereofand is adapted toreceive the vertically mounted cylinder |52 that is in turn providedwith an intake valve |53 in the head thereof. The crank arm 3B isdirectly secured to the outer wall of the cylinder in the manner similarto that in which the crank 38 is conected to cylinder 35 shown in Fig.1, except that such crank arm projects at an oblique angle with respectto the longitudinal axis of the cylinder in lieu of projecting yat rightangles therefrom as is the case in the construction shown in Figs. l and10.4

In lieu of controlling the flow of refrigerant through the system bymeans of inlet and exhaust check valves, either the inlet valve 50 orboth of these valves may be dispensed with. Inv

Fig. 13, we have illustrated an arrangementv whereby both of the checkvalves 25 and 50 have been eliminated and the flow of refrigerant'isdirected through different ports to inlet andl upper end andhas a spiralgroove |66 formed in its inner wall and a spiral slot |61 which extendsthrough lthe cylinder wall. Assuming the cylinder is rotating in thedirection indicated by the arrow in Fig. 13, and the parts are in theposition therein shown, which represents the start of a new cycle in theoperation of the compressor, the refrigerant chamber in the shell of thecompressor and the intake conduit |62 will be cut oi. As the cylindercontinues to rotate a slight suction will rst be created in cylinderhead and then the end v of slot |61 will come into registry with port|6| and refrigerant gas will be sucked through conduit |62 into the headof the cylinder and lthis will continue throughout the 'suction stroke,since the slot |61 is long enough to admit gas throughout the suctionstroke until the end of the suction stroke, at which time the end u ofslot |61 will pass out of registry with port |6| and further admissionof gas into the cylinder will be cut off. Upon the further rotation ofthe cylinder the compression stroke immediately commences and at suchtime-the lower end y of bridging groove |66 moves over port |63 butcompression of the gas in the cylinder continues until further rotationbrings said end y of such groove over or in registry with port |6|, atwhich time the pressure of the compressed gas will have reached thepoint where it is equal to or exceeds the pressure in the high side ofthe system, thus insuring lagainst backward ow of gas from high sideinto the compressor. Thereupon the compressed gas passes through conduit|62, port |6|, bridging groove |66 to port |63, conduit |64 and exhaustconduit I8 to the condenser, such flow continuing so long as thebridging groove covers both ports |6| and |63. Further rotation thencauses end :r of the groove |66 to pass beyond port |63 and therebyfurther passage of gas through the exhaust conduits |64 and i8 is cutofi. Upon further rotation another cycle of operations as abovedescribed occurs. The porting arrangement for controlling the flow ofrefrigerant is especially advantageous where the compressor is directlyconnected to an electric motor and is required to revolve at high speedsof say 1750 R.. P.`M. since it enables us to eliminate the objectionablefeatures of valve inertia or sluggishness so inherent when check valvesare employed. Furthermore, al1 noise due to the employment of checkvalves is eliminated and as a consequence the operation of thecompressor is remarkably silent.

In Fig. 16 we have shown diagrammatically a in the point of intersectionof the longitudinal axis of the shank with a diameter of the base of thepiston is ofi-center with respect to the center of said base. Theadvantage of this arrangement `is that it is possible to -so proportionthe stroke and position of the crank arm that sliding movement of thelatter, with respect to its universal joint or ball bearing, can beminimized, if not entirely eliminated. In this diagram, line a--brepresents the longitudinal axis of the obliqucly disposed, off-centershank of a piston P; c--d the longitudinal axis of the said piston anda: the point of intersection of these axes. The line e--f represents anormal to axis a-b drawn through point The line g-h represents a normalto axis c-d, along the plane of the bottom of the cylinder, to vthe linee-f and the distance :v -h will represent a length equal to onehalf ofthe cylinder stroke. Another line j-Ic is projected at right angles toaxis c-d, the distance z--f being equal to the distance :1t-h. As willbe apparent from the foregoing explanation of said diagram, the points gand k will represent the center of the ball bearing of crank arm atopposite ends of the stroke and since these points are equi-distant fromthe point x, there will be no sliding movement in the ball bearing ofthe crank arm, such as arm 3B of Fig. 1, the position of which willcoincide with the lines g--h and j-k at the different ends of thestroke. If, however, the longitudinal axis of the shank of the pistondoes not extend obliquely with respect to the longitudinal axis of thepiston and the point of piston having an obliquely disposed shank,whereintersection of such axis of the shank with the bottom of thepiston proper is not 01T -center with respect to the longitudinal axisofthe piston, it is not possible to prevent the crank armfrom sliding inits ball bearing.

If desired, the ball-bearing may be supported on the wall of thecylinder, or on the arm |34 employed in the construction shown in Fig.10, and the crank arm may be'rigidly connected to the section of theshell.

In Fig. 17 we have shown a modified form of crank arm 38' which has aterminal, eccentrically disposed cylindrical boss |10 formed thereon,which may be employed in lieu of crank arm 36, whereby the mounting ofthe ball in a nonadjustable socket member carried by the compressorshell on the cylnderor arm |34, may be tioning of the compressor in itsmounting and also the removal of the compressor from its mountingwithout uncoupling the pipes therefrom can be accomplished.

As will be apparent from the foregoing, the rotation of the shell of thecompressor shown in Fig. 1 by means of an electric motor which iscoupled thereto by a belt that is reeved in the pulley groove 5, willcause the cylinder 35 to move spirally on its supporting piston I6 and,as it moves upwardly, then due to the fact that the intake valve isnormally held off of its seat by the screw 59 until suchk time as thevelocity of rotation of the cylinder is sufficient to cause the weight4| under the urge of centrifugal force to y outwardly and lift saidscrew out of contact with such valve, the refrigerant gas will passbetween the shell of the compressor and the cylinder through the valve50 during the initial starting of the machine, since no compression ofthe gas within the cylinder can occur due to said valve 5U being held inan open position momentarily. As a result, the motor is relieved of allof the starting load or torque until such time as it attains full speedwhich, in the case of an electric motor operating at 1750 R. P. M., willoccur within a fraction of a second from the moment of starting.Consequently, it is not necessary to employ an expensive motor foroperating this machine, such vfor example as a repulsion-induction typeof motor or a capacitor type of motor, but in lieu thereof an ordinarycheap split-phase type of motor can be employed without anyobjectionable over-load being thrown thereon or any possibility of thefuse protecting such motor being blown due to any overloadingoccasionedby the inertia of rest of the parts of the compressor and the consequentstarting torque thereof. The upward spiral movement of the cylinder, aspreviously explained, creates a strong suction therein and refrigerantgas is drawn in through the valve 50 throughout the upward stroke of thecylinder. Due to the spiral movement of the cylinder on its piston,there will be no dead center at either end of the stroke, as the same ismoving continuously without any interruption throughout the entireoperation irrespective of thelreversal in the direction of movement ofthe cylinder on the piston. Upon the down stroke of the cylinder, thevalve 50 will close and valve 25, which has been previously closed, willopen and the compressed gas will be discharged through the exhaust pipe|8 into the condenser, thence passing to the sub-tank, thence to thepressure reducing or so-called expansion valve, thence to the evaporatorand back through the intake pipe and conduits 20 and I9 to the chamberWithin the compressor shell. In the construction shown in Fig. 10, theoperation will be 'similar to that of the compressor shown in Fig. l,except that the crank arm 38, being connected to the angular arm |34carried by the piston, will cause to and fro spiral movement of thepiston |32 in the -cylinder |30. In the construction shown in Fig.

1l, the cylinder |44 will be prevented from any spiral movement on thepiston |48, since the ring |46, which is carried by the crank arm 38,

can rotate in the oblique groove |41 and said piston being keyed to thecylinder, the latter can only reciprocate thereon. In the constructionshown in Fig. 21, the operation of the compressor will be substantiallyidentical with that "shown in Fig. 1, since in this case the crank arm3B is mounted obliquely on the cylinder- |52,

our improved refrigerating and air-conditioning unit, are the fact thatit employs no fly-wheel, since the compressor -shell functions as a flywheel and can be designed to be of a suitable weight to insure that the`machine will run smoothly without flickering of the lights occurring inthe lighting circuit which operates the machine. Also the piston shank,being integral, can be made of cast steel and can be bent to shapeeither before or after the machining thereof, and thus the employment ofan expensive forged crank shaft, such as formerly required in thereciprocating type compressors, can be avoided. Furthermore, noconnecting rod or wrist pins are employed which can Work loose or becomenoisy due to wear. The fact that we employ in our improved constructiona centrifugal unloader and the fact that as previously stated there isno dead center in the movement of the cylinder or its piston or, viceversa, in those cases where a moving piston is employed, it is possiblefor us to eliminate the objections commonly ymet with where it isattempted to employ an over-hung connection between the driving member,in this case the' shell of the compressor, and the cylinder, such forexample as the crank arm 38 which is secured to one side of the'cylinderand is actuated by the ball carried on the compressor shell, or viceversa, as heretofore explained. As a consequence, the operation of ourcompressor is extremely smooth and reliable even when employingrefrigerants which operate under extremely high pressures and, withoutthe association of the unloader, with compressors of this type, suchsmooth and reliable operation of the compressor could not beaccomplished with anything like the same degree of satisfaction. Thefact that the weighted element of the unloader is elastically mounted onthe pin 42 which is carried by the cylinder and not mounted on the lowerend of arm insures against vibration thereof, whereas were the samemountedon the arm 55, there would be a tendency for the same to chatterand develop objectionable noise.

Further advantages of our invention reside in the fact that there is adefinite amount of heat interchange between the hot exhaust gases andthe comparatively cool inlet gas passing through the shank of the pistonand the piston itself and thus the same are maintained'at a more normaltemperature and the over-heating of the oil between the bearingsurfacesis minimized, and thus -also 'the sealing elements aremaintained at a lower temperature. The aforesaid absence of any deadcenter in the movement of the cylinder or of the piston eliminates theusual knock that occurs in most all compressors of standardconstruction. Furthermore, since all bearing lack or looseness isdistributed over a wide segm ynt of the revolution of the cylinder, ascontrasted with the relatively narrow segment over which the same isdis-tributed in 'the ordinary reciprocating compressor, such slack orplay will be substantially absorbed and as a consequence not only is itpossible to eliminate the tedious' running-in operation which iscustomary to employ in the manufacture of compressors, but thecompressor will remain quiet in operation even after long periods ofuse. In our new compressor also the alignment of the moving parts ismuchA less of an important factor than in the standard reciprocatingcompressor, since it is a very simple matter to align the main bearingsand once the same are aligned, the universal ball joint emtomaticallycompensates for any rnisalignments such as might be caused by the slightvariations in the angularity of the piston, the cylinder or crank arm.Furthermore, since the cylinder rotates on the stationary piston in ourimproved construction, the operation of the machine is rendered muchquieter and furthermore the cost of manufacture of such a compressor, ascompared with a reciprocating type of compressor, wherein the cylinderis stationary, is reduced, due to the fact there is less precisionrequired in the machine work thereon. Since the ball ofthe universaljoint in which the crank arm is mounted is adjustable in its cup andalso because it is elastically mounted therein, no precision fitsbetween the ball and its socket are required and even after long use theoperation of these parts remains entirely quiet. As will be apparent,the heaviest pressure is exerted on the ball and crank arm in thedownward or compression stroke, and this is absorbed by the rigid ballcup while on the up or suction stroke, there is considerably lighterpressure exerted on such ball and this can be conveniently absorbed bythe spring mounting of such ball. By providing one-half of the pulleygroove on each segment of the shell of the compressor, it is possible tomaterially reduce the cost of turning a groove on such casing by meansof a forming tool. The fact that the cylinder assembly is Isealed withinthe crank case further tends to muilie any noise. The adjustment of thecylinder head clearance is accomplished by merely adjusting the ball cupof the ball joint either up or down and such adjustment takes care of awide range of jigging and machine variations, besides permitting of theexact clearance being maintained in all machines during manufacture bymaking a very simple adjustment. Still further advantages of ourinvention reside in the fact that due to the centrifugal projection ofthe oil to the outside of the chamber in the compressor case, the oilassumes a substantially hollow cylindrical form close'to the shell andsince the oil ipper terminates a short distance from` the shell, the oilreturned thereby is substantially free from grit, metal particles andthe like whichcollect in the extreme outer layer of such hollow cylinderof oil and consequently said oil layer is not only very substantiallycooled by contact with the rotating air-cooled shell of the compressor,but the portion of the oil which is recirculated through the system hasthe impurities thereof separated or removed by centrifugal action. 'Ihegland seal, becomes, in view of the vertical mounting of the4 compressorand the action of the oil flipper, a liquid seal thereby constitutingthe most effective type of gas seal and furthermore, even when thecompressor and motor are mounted horizontally, as sometimes may bedesirable, the oil flipper still tends to virtually maintain an oil sealaround the stationary shank, since the bearing and sealing elements arevirtually flooded at all times by the action of such flipper and thecentripetal force which returns the oil to the bearing. Furthermore, inthis same connection the centrifugal action or force exerted on the oiltends to prevent foaming or pumping of the oil as frequently occurs inother types of compressors. Not only is the oil positively pre- Ventedfrom reaching the inlet or exhaust valves of the cylinder which revolvewithin the hollow cylinder of the oil, but as a result of such action itis possible to employ much heavier oils without any objectionablefoaming occurring, with the consequence, that superior cushioning andlubrication of the parts is accomplished. The mounting employed for thecompressor is such that.

comparatively little metal-to-metal contact exists between it and thebase plate and as a consequence but little noise can betransmitted fromthe compressor to the base plate and thence to the refrigerator.Likewise the rubber mountings employed are such that there is but aminimum of contact between the supporting pins l02 and such mountingblocks, with a consequence that vibrations normal to gravity are verysubstantially absorbed.

If desired, in lieu of rotating the compressor shell, the shank andpiston carried thereby can be rotated and the shell maintainedstationary, but in such event it would be desirable to install aily-wheel on said shank besides making other minor necessary changes inthe valve arrangements and unloader and lubrication system.

Various modifications from the construction herein shown may be madewithout departing from the spirit of our invention as embraced withinthe scope of the appended claims.-

Having thus described our invention, what we claim and desire to obtainby United States Letters Patent is:

1.v In a'compressor, the combination comprising a rotatable shellforming a refrigerant receptacle, a cylinder element mounted in saidreceptacle and having a compression chamber that is periodicallyin-communication with the receptacle during the operation of thecompressor, a piston element mounted in said cylinder and relativelyreciprocatable with respect thereto, said piston having a shank elementwhich projects through said shell; oneof the said compressor elementsbeing stationary, but relatively rotatable with respect to the shell,and the other element being capable of rotation'and reciprocation withrespect to said stationary element,

driving means interconnecting one of said compressor -elements with saidshell and means for sealing the joint between said shell and said shankto prevent the escape of refrigerant therebetween.

2. :'In a compressor, the combination cornprising a hollow rotatabley-wheel whose external periphery is exposed to the atmosphere, includinga shell forming a refrigerant receptacle, a piston element and aco-operating cylinder element both mounted wholly in said fly-wheel, oneof said compressor elements being stationary, but relatively rotatablewith respect to the fly-wheel and the other element being capable ofrotation andl reciprocation with respect to said stationary element andthe shank of one of such pis- -Jton and cylinder elements projectingthrough the shell of the fly-wheel, driving means interconnecting one ofsaid compressor elements with said shell, valve-controlled means forperiodically admitting the passage of refrigerant uid from saidreceptacle to said cylinder during a suction stroke of the compressorand means for sealing the joint around said shank to prevent escape ofrefrigerant from said fly-wheel.

3. In a compressor, the combination comprising a rotatable shellforminga fluid receptacle therein, a piston element having a shank projectingthrough said shell, said piston extending suction stroke of thecompressor, whereby periodic compression of such iluid is accomplishedduring the to and fro movement of. the reciprocatable element, and meansfor sealing the joint between the shank and the shell adjacent theretoto prevent the escape of fluid therebetween.

4. In a compressor, the sub-combination comprising a rotatable shellforming a refrigerant receptacle, a piston element, a shank memberrigidly connected tosaid piston and which projects through said shell,said piston and cylinder both being located Wholly within said rotatableshell, a cylinder element mounted on said piston, one of the saidcompressor elements being stationary, but relatively rotatable withrespect to the shell, and the other element being capable of rotationand reciprocation with respect to said 4stationary element, means foradmitting refrigerant from the shell to the cylinder during the suctionstroke of the compressor, a crank arm interconnecting said shell andsaid cylinder, one end of said crank arm being mounted in asubstantially universal joint, and means for effecting spiral to and fromovement of said cylinder on said piston on rotation of said shell.

5. In a compressor, the sub-combination comprising a rotatable shell, apiston element pro'- jecting inwardly from a wall of said shell andhaving a shank portion projecting through said shell, a cylinder elementmounted on said piston, one of saidcompressorelements being stationary,but relatively rotatable with respect to the shell, and the otherelement being capable of rotation andreciprocation with -respect to saidstationary element, means for interconnecting said piston and said shelland means for effecting spiral to and fro movement of said cylinder onsaid piston on rotation of said shell.

6. In a compressor, the sub-combination comprising a hollow fly-wheelincluding a shell forming a refrigerant receptacle, co-'operating pistonand cylinder elements mounted in said fly-wheel and extending obliquelyinto -said receptacle, the shank of one of said elements extendingthrough f/sa'id shell, one of the said compressor elements piston andcylinder elements mounted therein.

one of said compressor elements being stationary. but relativelyrotatable with respect to the iiywheel, and the other element beingcapable of rotation and reciprocation with respect to said stationaryelement, means for admitting re-` frigerant from the interior of saidy-wheel'to the cylinder during the suction stroke of the compressor andmeans pivotally connecting one of said elements to said fly-wheel.

8. A compressor, comprising a hollow rotatable shell, an electric motorarranged to drive the same, co-operating piston and cylinder elementsmounted therein, one of the said compressor elements being stationary,but relatively rotatable vwith respect to the shell, and the otherelement being capable of rotation and reciprocation with respect to saidstationary element. overhung means projecting laterally from one of saidelements and connected to said shell, valvecontrolled means foradmitting refrigerant fromy said casing .to said cylinder during thesuction stroke of the compressor and unloading means carried by one ofsaid elements for relieving the motor circuit of undue overload whencircuit through the motor is initially closed` and the motor commencesto operate.

9. In a compressor, the combination comprising co-operating piston andcylinder elements, one of which is rotatable and the other stationary, amotor for rotating said rotatable element, inlet and exhaust valvesarranged to control the ow of refrigerant fluid to and from saidcylinder, and means for momentarily holding the inlet valve open whenthe said rotatable member commences to rotate to relieve the startingload otherwise imparted to said motor, said means including a slidable,elastically mounted weighted 10. In a compressor, the combination com-`prising a rotatable hollow shell, co-operating piston and cylinderelements mounted therein, means for connecting said casing to one of theco-operating elements and for effecting rotation of such element withrespect to the other cooperating element upon rotation of said shell andVmeans for returning oil from the zone adjacent the inner wall of theshell during its rotation, toward the center thereof.

11. In a compressor, the sub-combination comprising a rotatable shellforming a fluid receptacle, co-operating cylinder. and piston elementsextending obliquely to a major axis of said-shell, said cylinder andpiston elements being mounted wholly Within said receptacle, one of thesaid compressor elements being stationary, ybut relatively rotatablewith respect to the shell, and the other element being capable ofrotation and reciprocation with respect to said stationary element, acrank arm interconnecting said shell and one of said elements andarranged to effectspiral to and fro movement thereof on the otherelement. i

12. In a compressor, the combination comprising a rotatable hollowshell, co-operating piston and cylinder elements mounted therein, meansfor connecting said casing to one of the co-operating elements and foreffecting rotation of such element with respect to the other cooperatingelement upon rotation of said shell and means including an arcuate,longitudinally means l or periodically sealing and opening communicationbetween the interior of the cylinder and the respective inlet and outletconduits during the relative to and fro spiral movements o said pistonand cylinder elements.

14. In a compressor, the sub-'combination cornprising a rotatable shellforming a iluid receptacle, co-operating piston and cylinder elementsmounted in said receptacle, one of `the said compressor elements beingstationary, but relatively rotatable with respect to the shell, and theother element being capable of rotation and reciprocation with respectto said stationary element and means for connecting the shell to one ofsaid co-operatingelements to effect its reciprocation upon rotation ofsaid shell.

15. In a compressor, the sub-combination comprising a hollow rotatableshell forming a fluid receptacle, co-operating piston and cylinderele--l ments mounted within said receptacle, one of the said compressorelements being stationary, but relatively rotatable with respect to theshell, and the other element being capable of both rotation andreciprocation on said stationary element and means, including a crankarm, for connecting the movable element to said shell to effectreciproca.- tion of said movable element simultaneously with therotation of said shell.

16. In a compressor, the sub-combination comprising a hollow rotatableshell forming a fluid receptacle, co-operating piston and cylindermembers mounted within said receptacle, one of said members beingreciprocatable and the other immovable and serving as a guide for theother during its reciprocation; and means, including a vcrank arm and aball-and-socket joint, for connecting the reciprocatable member to saidshell to effect reciprocation of said movable member simultaneously withthe, rotation of said shell, said socket being adjustable longitudinallyin a plane that includes said crank arm.

17. In a compressor, the sub-combination comprising a shell forming arefrigerant chamber, cri-operating piston vand cylinderv elementsassociated therewith, valve-controlled means affording communicationbetween said chamber and said cylinder, one of said compressor elementsbeing stationary and the other movable, and means, including a rotatablymounted universal joint connected to said movable element, for eiectingreciprocation of. said movable element and also for simultaneouslyeffecting its rotation about an axis oblique to the axis of rotation ofsaid universal joint.

18. In a compressor, the sub-combination come prising piston andcylinder elements, one of 'which 4is mounted so as to remain stationaryduring the operation of the compressor and the other of which is movablymounted, a rotor memberand rotation and reciprocation of said movableelement.

19. In a compressor, the sub-combination com prising piston and cylinderelements, one of which is mounted so as to remain stationary during theoperation of the compressor and the other of which is movably mounted, arotor member, means including a connecting rod and a universal jointconnecting saidfmovable ele-A ment and said rotor and for positivelyeiecting the simultaneous and continual rotation and reciprocation ofsaid movable element, such reciprocation being along an axis extendingobliquely to the axis of rotation of said rotor member.

20. In a' compressor, the sub-combination comprising a rotor,reciprocatably and rotatably associated piston and cylinder elements andthe axis of each of which projects at an oblique angle to the'axis ofthe rotor and a universal joint con- ,'ncction loosely connecting one ofsaid elements to said rotor.

21. In a compressor unit, the combination com prising an hermeticallysealed housing, compressor elements including a piston and cylindermounted therein, means including a crank arm and a universal joint foreffecting simultaneous rotation and reciprocation of said compressorelements relative to each other, means for affording communicationbetween the interior of said'cylinder and the interior of said housingsurrounding the same during the suction stroke of compressor, means foradmitting fluid from an external source into said housing and meansA forconducting compressed fluid' directly from said cylinder to a pointexternal of said housing.

22. In a compressor, the sub-combination comprising piston and cylinderelements rotatably and reciprocatably associated together, a. rotor anda universal joint connection, including a recof said elements to saidrotor.

23. In a compressor, the sub-combination comprising piston and cylinderelements rotatably and reciprocatably associated together, a rotor andmeans, including a longitudinally slidable element, operativelyinter-connecting said rotor and one of said piston and cylinder elementsconstraining such element to turn with the rotor and to effect relativereciprocatlonbetween the said associated elements.

24. In-a compressor, the sub-combination comprising a motor including arotor, piston and cylinder elements reciprocally and rotatablyassociated with ea'ch other, the axis of each of which elements projectsat an angle to a plane that is normal to the axis of rotation of saidrotor and a flexible joint connection including aA reciprocable slidemember for connecting one o fA trically associated piston and cylinderelements whose` longitudinal axes respectively extend at an angle to aplane that is normal to the axis of.

` rotation of said rotor, said elements being both relativelyreciprocable and relatively rotatable with respect to each other,means'including a reciprocable slide member for'connecting one :f saidelements to said rotor whereby: to constrain such element .to rotate andreciprocate with respect to the other element upon rotation of saidrot'or, said piston constituting valve means operable during therelative rotation of the piston element with respect to the cylinderelement and said cylinder element having a duct extending completelythrough its lateral wall and which is A necting one -of said elements tosaid rotor whereby to constrain such element to rotate and reciprocatewith respect to the other element upon rotation of said rotor, saidpiston constituting valve means operable duringthe relative rotation ofthe piston element with respect to the cylinder element and having aduct which extends completely therethrough from its lateral face to andthrough the face of its head end and said cylinder element having a ductwhich extends completely through its lateral wall and one of the ductsof said cylinder and piston elements terminating in ia spiral surfacegroove which is adapted to periodically register with a terminal port ofthe duct in the other element during the reciprocation and rotation ofthe cylinder elei'nents.

SYLVESTER A. LIMPERT. ALEXANDER S. LIMPERT.

